Geographical display of health information: study of hepatitis C infection in Karachi, Pakistan.

The prevalence of hepatitis C and other infections is increasing in urban areas of developing countries. Data on such diseases are often limited to facility-based information. However, even this is not available in a usable form to health care providers, health managers and policy makers. We present a simple technique for visually displaying facility based prevalence information on hepatitis C using basic geographic information system (GIS) techniques. We display the prevalence of hepatitis C for the city of Karachi, Pakistan for the first time. The distribution tends to indicate that there are areas of higher prevalence located in specific districts. There is also a trend of higher prevalence in less affluent urban areas. Such simple applications of mapping technology are useful for rapidly summarizing and displaying information in a contextually and spatially meaningful fashion, and its use should be encouraged for displaying health indicators in developing countries.